As an advocate for and practioner of blogging since 1999 and I couldn't let this pass by (even though I am meant to be writing at TMA that is due today).
Search 'blog' or 'blogging' in my OU Student Blog (here) or click on one of the tags.
The research shows that in the overall active online community of many millions online:
95% read (lurk/observe/consume blogs)
4% will go one step further and engage (i.e. add a comment)
1% actually 'create' (write essentially, though this may now include blogs that are essentially photogalleries or YouTube uploads)
Neilsen, J (2011).
In the student population (the study was last done in 2009 with undergraduates in Australia), the figure rises to 34% having uploaded content to a blog ... 'in the last 12 months'. (which for my money means they are not blogging at all).
Good luck, enjoy!
They have a multitude of uses and value and I will of course say that this value greatly increases over time.